Effect of angiotensin II receptor blockade on proximal tubular fluid reabsorption.

P P Leyssac; F M Karlsen; N H Holstein-Rathlou

Effect of angiotensin II receptor blockade on proximal tubular fluid reabsorption.

P P Leyssac, F M Karlsen, N H Holstein-Rathlou

Biomedicinsk Institut

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

13 Citationer (Scopus)

Abstract

Udgivelsesdato: 1997-Aug

Originalsprog	Engelsk
Tidsskrift	American Journal of Physiology (Consolidated)
Vol/bind	273
Udgave nummer	2 Pt 2
Sider (fra-til)	R510-7
ISSN	0002-9513
Status	Udgivet - 1997

Bibliografisk note

Keywords: Absorption; Animals; Biphenyl Compounds; Body Fluids; Imidazoles; Kidney Tubules, Proximal; Losartan; Male; Perfusion; Pressure; Rats; Rats, Sprague-Dawley; Receptors, Angiotensin; Sodium Chloride; Tetrazoles

Citationsformater

@article{dfa08550abf111ddb5e9000ea68e967b,

title = "Effect of angiotensin II receptor blockade on proximal tubular fluid reabsorption.",

abstract = "The effect of physiological concentrations of angiotensin II on proximal tubular fluid reabsorption remains controversial. To investigate the effect of blockade of intratubular AT1 receptors on tubular reabsorption, losartan (10(-5) M) was administered by microperfusion into an early proximal convolution of halothane-anesthetized Sprague-Dawley rats. Four parameters that depend on the rate of proximal fluid reabsorption were measured: proximal intratubular pressure (Pprox), early and late proximal flow rate, and early distal NaCl concentration. Pprox decreased by 0.5 +/- 0.1 mmHg, late proximal flow rate decreased by 2.0 +/- 0.8 nl/min, and early distal NaCl concentration decreased by 4.3 +/- 0.8 mM (mean +/- SE). No changes were observed after microperfusion with saline. Because the tubuloglomerular feedback mechanism was operating in the closed-loop mode, the decreased NaCl load to the macula densa will be compensated by an increase in the single-nephron glomerular filtration rate. In agreement with this, the early proximal flow rate, measured proximal to the site of losartan administration, increased by 5.7 +/- 1.3 nl/min. The increase in the rate of proximal reabsorption between the early and late proximal convolutions was estimated to be 7.8 nl/min (approximately 36%). It is concluded that a decrease in local luminal angiotensin II levels and/or AT1 receptor activity under free flow conditions increases the rate of proximal tubular fluid reabsorption.",

author = "Leyssac, {P P} and Karlsen, {F M} and Holstein-Rathlou, {N H}",

note = "Keywords: Absorption; Animals; Biphenyl Compounds; Body Fluids; Imidazoles; Kidney Tubules, Proximal; Losartan; Male; Perfusion; Pressure; Rats; Rats, Sprague-Dawley; Receptors, Angiotensin; Sodium Chloride; Tetrazoles",

year = "1997",

language = "English",

volume = "273",

pages = "R510--7",

journal = "American Journal of Physiology - Cell Physiology",

issn = "0363-6143",

publisher = "American Physiological Society",

number = "2 Pt 2",

}

TY - JOUR

T1 - Effect of angiotensin II receptor blockade on proximal tubular fluid reabsorption.

AU - Leyssac, P P

AU - Karlsen, F M

AU - Holstein-Rathlou, N H

N1 - Keywords: Absorption; Animals; Biphenyl Compounds; Body Fluids; Imidazoles; Kidney Tubules, Proximal; Losartan; Male; Perfusion; Pressure; Rats; Rats, Sprague-Dawley; Receptors, Angiotensin; Sodium Chloride; Tetrazoles

PY - 1997

Y1 - 1997

N2 - The effect of physiological concentrations of angiotensin II on proximal tubular fluid reabsorption remains controversial. To investigate the effect of blockade of intratubular AT1 receptors on tubular reabsorption, losartan (10(-5) M) was administered by microperfusion into an early proximal convolution of halothane-anesthetized Sprague-Dawley rats. Four parameters that depend on the rate of proximal fluid reabsorption were measured: proximal intratubular pressure (Pprox), early and late proximal flow rate, and early distal NaCl concentration. Pprox decreased by 0.5 +/- 0.1 mmHg, late proximal flow rate decreased by 2.0 +/- 0.8 nl/min, and early distal NaCl concentration decreased by 4.3 +/- 0.8 mM (mean +/- SE). No changes were observed after microperfusion with saline. Because the tubuloglomerular feedback mechanism was operating in the closed-loop mode, the decreased NaCl load to the macula densa will be compensated by an increase in the single-nephron glomerular filtration rate. In agreement with this, the early proximal flow rate, measured proximal to the site of losartan administration, increased by 5.7 +/- 1.3 nl/min. The increase in the rate of proximal reabsorption between the early and late proximal convolutions was estimated to be 7.8 nl/min (approximately 36%). It is concluded that a decrease in local luminal angiotensin II levels and/or AT1 receptor activity under free flow conditions increases the rate of proximal tubular fluid reabsorption.

AB - The effect of physiological concentrations of angiotensin II on proximal tubular fluid reabsorption remains controversial. To investigate the effect of blockade of intratubular AT1 receptors on tubular reabsorption, losartan (10(-5) M) was administered by microperfusion into an early proximal convolution of halothane-anesthetized Sprague-Dawley rats. Four parameters that depend on the rate of proximal fluid reabsorption were measured: proximal intratubular pressure (Pprox), early and late proximal flow rate, and early distal NaCl concentration. Pprox decreased by 0.5 +/- 0.1 mmHg, late proximal flow rate decreased by 2.0 +/- 0.8 nl/min, and early distal NaCl concentration decreased by 4.3 +/- 0.8 mM (mean +/- SE). No changes were observed after microperfusion with saline. Because the tubuloglomerular feedback mechanism was operating in the closed-loop mode, the decreased NaCl load to the macula densa will be compensated by an increase in the single-nephron glomerular filtration rate. In agreement with this, the early proximal flow rate, measured proximal to the site of losartan administration, increased by 5.7 +/- 1.3 nl/min. The increase in the rate of proximal reabsorption between the early and late proximal convolutions was estimated to be 7.8 nl/min (approximately 36%). It is concluded that a decrease in local luminal angiotensin II levels and/or AT1 receptor activity under free flow conditions increases the rate of proximal tubular fluid reabsorption.

M3 - Journal article

C2 - 9277533

VL - 273

SP - R510-7

JO - American Journal of Physiology - Cell Physiology

JF - American Journal of Physiology - Cell Physiology

SN - 0363-6143

IS - 2 Pt 2

ER -